Issue search support elasticsearch (#9428)

* Issue search support elasticsearch

* Fix lint

* Add indexer name on app.ini

* add a warnning on SearchIssuesByKeyword

* improve code

modules/indexer/issues/elastic_search.go

@@ -0,0 +1,230 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package issues
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strconv"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+
+	"github.com/olivere/elastic/v7"
+)
+
+var (
+	_ Indexer = &ElasticSearchIndexer{}
+)
+
+// ElasticSearchIndexer implements Indexer interface
+type ElasticSearchIndexer struct {
+	client      *elastic.Client
+	indexerName string
+}
+
+type elasticLogger struct {
+	*log.Logger
+}
+
+func (l elasticLogger) Printf(format string, args ...interface{}) {
+	_ = l.Logger.Log(2, l.Logger.GetLevel(), format, args...)
+}
+
+// NewElasticSearchIndexer creates a new elasticsearch indexer
+func NewElasticSearchIndexer(url, indexerName string) (*ElasticSearchIndexer, error) {
+	opts := []elastic.ClientOptionFunc{
+		elastic.SetURL(url),
+		elastic.SetSniff(false),
+		elastic.SetHealthcheckInterval(10 * time.Second),
+		elastic.SetGzip(false),
+	}
+
+	logger := elasticLogger{log.GetLogger(log.DEFAULT)}
+
+	if logger.GetLevel() == log.TRACE || logger.GetLevel() == log.DEBUG {
+		opts = append(opts, elastic.SetTraceLog(logger))
+	} else if logger.GetLevel() == log.ERROR || logger.GetLevel() == log.CRITICAL || logger.GetLevel() == log.FATAL {
+		opts = append(opts, elastic.SetErrorLog(logger))
+	} else if logger.GetLevel() == log.INFO || logger.GetLevel() == log.WARN {
+		opts = append(opts, elastic.SetInfoLog(logger))
+	}
+
+	client, err := elastic.NewClient(opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ElasticSearchIndexer{
+		client:      client,
+		indexerName: indexerName,
+	}, nil
+}
+
+const (
+	defaultMapping = `{
+		"mappings": {
+			"properties": {
+				"id": {
+					"type": "integer",
+					"index": true
+				},
+				"repo_id": {
+					"type": "integer",
+					"index": true
+				},
+				"title": {
+					"type": "text",
+					"index": true
+				},
+				"content": {
+					"type": "text",
+					"index": true
+				},
+				"comments": {
+					"type" : "text",
+					"index": true
+				}
+			}
+		}
+	}`
+)
+
+// Init will initialize the indexer
+func (b *ElasticSearchIndexer) Init() (bool, error) {
+	ctx := context.Background()
+	exists, err := b.client.IndexExists(b.indexerName).Do(ctx)
+	if err != nil {
+		return false, err
+	}
+
+	if !exists {
+		var mapping = defaultMapping
+
+		createIndex, err := b.client.CreateIndex(b.indexerName).BodyString(mapping).Do(ctx)
+		if err != nil {
+			return false, err
+		}
+		if !createIndex.Acknowledged {
+			return false, errors.New("init failed")
+		}
+
+		return false, nil
+	}
+	return true, nil
+}
+
+// Index will save the index data
+func (b *ElasticSearchIndexer) Index(issues []*IndexerData) error {
+	if len(issues) == 0 {
+		return nil
+	} else if len(issues) == 1 {
+		issue := issues[0]
+		_, err := b.client.Index().
+			Index(b.indexerName).
+			Id(fmt.Sprintf("%d", issue.ID)).
+			BodyJson(map[string]interface{}{
+				"id":       issue.ID,
+				"repo_id":  issue.RepoID,
+				"title":    issue.Title,
+				"content":  issue.Content,
+				"comments": issue.Comments,
+			}).
+			Do(context.Background())
+		return err
+	}
+
+	reqs := make([]elastic.BulkableRequest, 0)
+	for _, issue := range issues {
+		reqs = append(reqs,
+			elastic.NewBulkIndexRequest().
+				Index(b.indexerName).
+				Id(fmt.Sprintf("%d", issue.ID)).
+				Doc(map[string]interface{}{
+					"id":       issue.ID,
+					"repo_id":  issue.RepoID,
+					"title":    issue.Title,
+					"content":  issue.Content,
+					"comments": issue.Comments,
+				}),
+		)
+	}
+
+	_, err := b.client.Bulk().
+		Index(b.indexerName).
+		Add(reqs...).
+		Do(context.Background())
+	return err
+}
+
+// Delete deletes indexes by ids
+func (b *ElasticSearchIndexer) Delete(ids ...int64) error {
+	if len(ids) == 0 {
+		return nil
+	} else if len(ids) == 1 {
+		_, err := b.client.Delete().
+			Index(b.indexerName).
+			Id(fmt.Sprintf("%d", ids[0])).
+			Do(context.Background())
+		return err
+	}
+
+	reqs := make([]elastic.BulkableRequest, 0)
+	for _, id := range ids {
+		reqs = append(reqs,
+			elastic.NewBulkDeleteRequest().
+				Index(b.indexerName).
+				Id(fmt.Sprintf("%d", id)),
+		)
+	}
+
+	_, err := b.client.Bulk().
+		Index(b.indexerName).
+		Add(reqs...).
+		Do(context.Background())
+	return err
+}
+
+// Search searches for issues by given conditions.
+// Returns the matching issue IDs
+func (b *ElasticSearchIndexer) Search(keyword string, repoIDs []int64, limit, start int) (*SearchResult, error) {
+	kwQuery := elastic.NewMultiMatchQuery(keyword, "title", "content", "comments")
+	query := elastic.NewBoolQuery()
+	query = query.Must(kwQuery)
+	if len(repoIDs) > 0 {
+		var repoStrs = make([]interface{}, 0, len(repoIDs))
+		for _, repoID := range repoIDs {
+			repoStrs = append(repoStrs, repoID)
+		}
+		repoQuery := elastic.NewTermsQuery("repo_id", repoStrs...)
+		query = query.Must(repoQuery)
+	}
+	searchResult, err := b.client.Search().
+		Index(b.indexerName).
+		Query(query).
+		Sort("id", true).
+		From(start).Size(limit).
+		Do(context.Background())
+	if err != nil {
+		return nil, err
+	}
+
+	hits := make([]Match, 0, limit)
+	for _, hit := range searchResult.Hits.Hits {
+		id, _ := strconv.ParseInt(hit.Id, 10, 64)
+		hits = append(hits, Match{
+			ID: id,
+		})
+	}
+
+	return &SearchResult{
+		Total: searchResult.TotalHits(),
+		Hits:  hits,
+	}, nil
+}
+
+// Close implements indexer
+func (b *ElasticSearchIndexer) Close() {}